U.S. Pat. No. 4,907,987 discloses a connector with a barbed board lock including a metal member having barbs supported by spring elements that bite into interior wall surfaces of circuit board holes to lock a connector thereto. The patent teaches a variety of constructions for locking a connector and a circuit board together.
U.S. Patent application Ser. No. 07/621,407 teaches an improved board locking device wherein a planar stamped metal member includes spring beams projecting in opposite directions from a center horizontal projection. The horizontal projection engages horizontal surfaces within the components that are to be secured together. One the spring beams is secured within a cavity within a first component and the other spring beam is secured within a cavity of a second component to latch to two components together in a fixed manner. Each of the spring members have a plurality of outwardly extending barbs that engage the interior wall surfaces of the respective cavities within the components. The securing or holding power of these devices is primarily dependent upon the spring rate of the material from which the device is made as well as the shape of the spring members.
In designing board locks or other retention devices, it is desirable to minimize the amount of insertion force required to secure to two components together and at the same time maximize the retention force holding the components together. It is further desirable that a retention device be self seating that is requiring no tools to operate the device.